Across
- 2. two of these split off from the trachea
- 4. cells that carry water around a plant
- 6. the number and appearance of chromosomes
- 7. when a hot fluid rises and a cold one sinks
- 9. the unit of pressure
- 11. part of the cell where respiration is carried out
- 17. the opposite of repel
- 19. when a species dies out
- 20. the green pigment in plant leaves
- 21. reaction in which a substance combines with oxygen
- 23. pores that allow gases into leaves
- 24. a disease when a person has an extra chromosome
- 25. horizontal row in the periodic table
Down
- 1. the change in a species over a long time period
- 3. the unit of force
- 5. measured in degrees celcius
- 8. separating compounds using electricity
- 10. what is made in a chemical reaction
- 12. bones that protect the lungs
- 13. chemical used to test for starch
- 14. glucose molecules linked in a chain
- 15. the smallest blood vessel
- 16. put on soil to improve plant growth
- 17. the mixture of gases around the Earth
- 18. turns to show the direction of a magnetic field
- 22. when a force tries to stretch something